Discovery, Detection, and Management of Daisy-Chain System Topology

1. A method of auto-discovery and auto-enumeration, the method comprising: identifying each port of each device in a daisy-chain system of serially inter-connected devices, wherein identifying each port of each device further comprises: detecting a link status change on one of the ports on one of the devices in the daisy-chain system; if a packet is received on the port having the link status change during a predetermined interval of time, defining the port as a first boundary port; discovering each device in the daisy-chain system; if a packet is not received on the port during the predetermined interval of time, further comprising: sending an auto-negotiation message to a neighboring device in the system; if the same message is received in return from the neighboring device, defining the port as an internal port; and if the same message is not received in return from the neighboring device, defining the port as a first boundary port; and enumerating each device in the daisy-chain system.

2. The method of claim 1 , further comprising managing the daisy-chain system by executing commands issued by any device in the daisy-chain system if the device has been granted use of a control token.

3. The method of claim 1 , wherein discovering each device in the daisy-chain system further comprises generating and propagating a propagation packet.

4. The method of claim 1 , further comprising building a device list of the devices in the system and storing the device list locally on each device.

5. A method of auto-discovery and auto-enumeration, the method comprising: identifying each port of each device in a daisy-chain system of serially inter-connected devices, wherein identifying each port of each device further comprises: detecting a link status change on one of the ports on one of the devices in the daisy-chain system; if a packet is received on the port having the link status change during a predetermined interval of time, defining the port as a first boundary port; discovering each device in the daisy-chain system, if a packet is not received on the port during the predetermined interval of time, further comprising: changing content stored in an auto-negotiation register for the port in a predetermined sequence; comparing the predetermined sequence to an advertised sequence of changes made to an auto-negotiation register for the connected port of a neighboring device; if the sequences are the same, defining the port as an internal port; and if the sequences are not the same, defining the port as a first boundary port; and enumerating each device in the daisy-chain system.

6. The method of claim 5 , wherein enumerating each device in the system further comprises: assigning an identification number to the device of a second boundary port device; and at each device, assigning an identification number to each device that is one less than the identification number of the previous device in the system.

7. The method of claim 5 , wherein enumerating each device in the system further comprises generating a discovery enumeration packet at a second boundary port device; and forwarding the enumeration packet to each device in the system until the enumeration packet is received by the first boundary port device.

8. The method of claim of claim 6 , wherein discovering and enumerating each device is initiated by a master device in the system, wherein the master device is selected based on a comparison of a Media Access Control (“MAC”) address for the first boundary device and a Media Access Control (“MAC”) address of the second boundary device.

9. A device, comprising: an ethernet switch having at least two ports; a control logic operable to: identify each of the ports as an internal port or a boundary port, wherein in identifying each of the ports as an internal port or a boundary port, the control logic is further operable to: detect a link status change on one of the ports; if a packet is received on the port during a predetermined interval of time, define the port as a first boundary port, discover any device connected in a daisy-chain fashion to any identified internal port; wherein in identifying each of the ports as an internal port or a first boundary port, the control logic is further operable to: send an auto-negotiation message to a neighboring device; if the same auto-negotiation message is received in return from the neighboring device, define the port as an internal port; and if the same auto-negotiation message is not received in return from the neighboring device, define the port as the first boundary port; and enumerate any such discovered device connected in a daisy-chain fashion to any identified internal port.

10. The device of claim 9 , wherein in identifying each of the ports as an internal port or a first boundary port, the control logic is further operable to: change content stored in an auto-negotiation register for the port in a predetermined sequence; compare the predetermined sequence to an advertised sequence of changes to an auto-negotiation register for a neighboring port of a neighboring device connected to the port of the device; if the sequences are the same, define the port as an internal port; and if the sequences are not the same, define the port as the first boundary port.

11. The device of claim 9 , wherein in discovering any device connected in a serial fashion to any identified internal port, the control logic is further operable to generate and propagate a propagation packet.

12. The device of claim 9 , wherein in enumerating any such discovered device, the control logic is further operable to assign an identification number to the device where the identification number is equal to the total number of devices connected via an internal port if the device identifies at least one of its ports as a first boundary port and the device is not a master device.

13. The device of claim 9 , wherein in enumerating any such discovered device, the control logic is further operable to assign an identification number to the device equaling one if the device identifies at least one of its ports as a first boundary port and the device is a master device.

14. The device of claim 9 , wherein in enumerating any such discovered device, the control logic is further operable to assign an identification number that is one less than the identification number of the most recent previously enumerated device in the system if the device identifies both of its ports as internal ports.

15. The device of claim 14 , wherein in enumerating any such discovered device, the control logic is further operable to generate a discovery enumeration packet at any port identified as a first boundary port, and forward the discovery enumeration packet to any device connected via an internal port.

16. A daisy-chain system, comprising: a plurality of devices inter-connected together in a daisy-chain; the boundaries of the system defined by a first boundary port of a first device in the system and a second boundary port of a second device in the system; each device operable for auto-discovery and auto-enumeration, each device comprising: an ethernet switch having at least two ports; a control logic operable to: identify each of the ports as an internal port or a boundary port; discover any device connected in a daisy-chain fashion to any identified internal port; and enumerate any such discovered device connected in a daisy-chain fashion to any identified internal port, detect a link status change on one of the ports; if a packet is received on the port during a predetermined interval of time, define the port as a boundary port; if a packet is not received on the port during the predetermined interval of time, implement at least one of the following auto-negotiation techniques: 1) send an auto-negotiation message to a neighboring device; if the same message is received in return from the neighboring device, define the port as an internal port; and if the same message is not received in return from the neighboring device, define the port as a boundary port; and 2) change content stored in an auto-negotiation register for the port in a predetermined sequence; compare the predetermined sequence to an advertised sequence of changes to an auto-negotiation register for a neighboring port of a neighboring device connected to the port of the device; if the sequences are the same, define the port as an internal port; and if the sequences are not the same, define the port as a boundary port.

17. The daisy-chain system of claim 16 , wherein the control logic is further operable to: detect a topology change in the daisy-chain system; and propagate the topology change to each device in the daisy-chain system; wherein the topology change comprises at least one of 1) an additional device is connected to the daisy-chain system, 2) a device is disconnected from the daisy-chain system, 3) a device in the daisy-chain system is powered on, and 4) a device in the daisy-chain system is powered off.

18. The daisy-chain system of claim 16 , wherein the control logic is further operable to generate and forward a propagation packet to each device in the system, and generate and forward an enumeration packet to each device in the system.